Change-speed gearing.



G. T. CAVILL.

CHANGE SPEED GEARING.

APPLIUATIoN FILED 1E1s,15, 1911.

Patented Dc. 1o, 1912.

3 SHEETS-SHEET 1.

Witnesses:

y Qjud @w- G. T. CAVILL.

CHANGE SPEED GEABING.

APPLIOATION FILED mmm, 1911.

1,046,552. Patented Dec. 1o,1912.

S'SHEETS-BHEET 2.

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Y element `a cross section Unrrn sfrnrns PATENT' ernten.

. GEORGE THOMAS CAVILL, 0F SYDNEY, NEW SOUTH WALES, AUSTRALIA.

Application led February 15, 1911.

' To (1.7.7, whom it may concern.: y

Be it known that I, GEORGE THOMASA C xvim., a subject of the King of Great Britain and Ireland', residing at 46 Dawson street, Surry Hills, Sydney, in the State of New South lVales, Australia, have invented certain new and useful Improvements in Change-Speed Gearing, of which the following isa specification.

My invention relates to toothed gearing for transmitting rotary motion, and particularly to that class of such gearing in which the driving and driven gears are mounted permanently .'n mesh, and in which any required one of the driving gears may be engaged to the driving element by a clutch while the other driving gears remain free, whereby a change in the speed ratio as between the driving and the driven element is obtained. Such gearing is used chiefly in automobiles, but is applicable also in lathes land other machinery 1n which a variable controllable relation is required between the driving and the driven elements.

ln this. speciication `the term driving is applied to the engine or to a rotating part directly connected thereto, and driven element to an axle or shaft or othery part which receives motion through the gearing from the driving element.

l My principal object of the invention is toprovide a form of mechanism in vwhich toothed gears locatedv intermediate between the driving element and the driven element in an auto-mobile or other transmissionsystem of variablev speed gearing may be changed readily, positively, and smoothly during running. without moving any of the intergeared wheels out of lmesh; and in which also the road wheels or ldriven ele- `ment will be gearedA automatically directly y to the engine shaft when the rotational speed of the driven element exceeds the engine speed,`thereby permitting the retardation of the engine to be used for braking purposes.

In'the accompanying drawings, Figure 1 is a horizontal section through gearing mechanism accordingto my invention adaptautomobile; Fig. 2 is a perspective view of the mechanism shown inFig. 1, part of the upper casing and the yokes and yoke stem of the reversing mechanism not being shown; Fig. 3 is a vfragment perspective view illustrating detail of the`reversing mechanism; Fig.; 4 is Specification of Letters Patent.

which clutch illustrative of the construe-- Patented Dec. 10, 1912.

Serial No. 608,822.

tion of t-he contracting clutch; Fig. 5 is a fragment section illustrating a preferred modificationV of the construction of parts associated with the pick-up clutch by which the driven element is geared to the driving element when the speed of the driven element becomes excessive; Fig. 6 is a transverse section through the coupler shaft and one of the externally castellated tubular shafts; and Fig. 7 is a view of the manual lever for operating the clutch rod.

1 is thercasing containing suitable bean ings 2 and 3 for the counter shaft 4.-, and 5' and 6 for the gear end* of the driving shaft 7 and for the other end of the coupler shaft 8. 9 is thedriven member, which is rotated by a toothed wheel 11 on the end of the coupler shaft 8. l l

13 is a tubular shaft made hexagonal or castellated externally or fitted with a feather key; it is rotatable upon the' forward end -of the coupler shaft 8; this tubular shaft 13 is coupled by means of the keyed collar 14 to the drum 15 which is on the end of the engine .clutch shaft 7. 16 is a collar keyed at 17 to the coupler shaft 8. The collar drum 15 is formed interiorly with a number of inclined faces such as 18, Fig. 4, said faces fo-rming the top sides of pockets 19 within rollers 20 (88 in Fig. 1) are set looselI The inclined faces 18 are arranged anti-clockwise; that are so arranged that when the shaft 7 tends to turn faster than but in the same direction as the shaft 8, the rollers 83will run free, but when the shaft 8 should turn faster than and in the same direction as the shaft 7, as will be 'the case when the car moves fast while the engine is slowed up, then ytheY rollers 83 engage the collar 16, as in A'a free wheel clutch, and the gearing tendsjto drive the engine, under which circumstances the retardation of the engine may be used as a. braking force. In the construction shown in Fig. 5, which is` in all respects substantially identical in principle bf construction and function of parts with the arrangement shown in Fig. 1, the driving collar 21 which is keyed at 22 to the coupler shaft 8, is made as a drum, and the end off-the driving shaft 7 is made tubular asshown at 23, and formed at its extreme end 24 to set into the drum collar 21, the end of the coupler shaft being journaled in the tubular shaft 23. Either the part 24 or the hollow ring of the collar 21 has a. number Of-inclined faces similar is to say, they to 18 cut in it, and rollers 25 similar to the rollers 20, Fig. 4, are set in the intermediate pockets (see 19, Fig. 4); theserollers coacting between the opposed inclined "andcylindrical faces of the parts 21and 24 form a 'clutch by which the coupler shaft 8- is connected automatically to the driving shaft 7 whenever thelrotational speed of the coupler shaft 8 exceeds the speed of the driving shaft 7. v=.The tubular shaft 13 (Fig. 1), or, ,as the 'case may be, the tubular shaft 23 (Fig. 5) is castellated exteriorly. Upon it is slidably mounted the sleeve 26 of the main clutch 27; this sleeve is formed `interiorly to engage the castellations of the tubular shaft 13 (or 23), so that while the clutch 27 is slidable longitudinally in Arelation to the .other parts it will always be rotated by the shaft 13 (or 23) irrespective lof its position v aloner said shaft.

28 is a. t-ubular shaft mounted upon and freely rotatable about the coupler lshaft 8; this tubular shaft 28 is itted with a cylindrical collar 29 at its forward end,-and at its rear end,with a gear wheel 301; upon it in .-turn is rotatably mountedanother tubular shaft 31 which 4is similarly providedl with a cylindrical collar 32 at its forward end and.

- with a gear 'Wheel 33 at its .rear end; another ment with, any one clutch, and so the tubular shaft` 34, the external diameter of which corresponds with the external diameters of the collars 21, 29, and 32, is rotatablyv mounted upon the tubular shaft`31, and at tlierear end this tubular shaft 34 carriesa gear wheell VIntermediate between-` th tubular shaft 34 and the collar 32 is a loose ring 36. The peripheral faces of the-collars 21, 29 and 32, as Well as the peripheral faces`of the ring 36 and ofthe shaft 34, are all in line, in order that the yrollers in the main4 clutch 27 may be slid endwise over those several parts and Set in alinenientwith anyone of them as required, to engage the same. When the rollerscontained 1n the engaging clutch' 2,7are brought into alineof these arts` by sliding the clutch27 axiall' the col ar'in alinement with they clutch rol ers 2O isgengaged by the engine shaft jsconnecte'd up to the toothed gear or-set on the neutral l ring k36 asre uired. On the countershft |4 are keyed t reegear.,whels`37, 38, and 39; thewheel 30 engages the wheel 38; the wheel 33 engages the wheel 37 and the wheel the wheel 39. There is a lay shaft 93 below which carries 'a double toothed wheel '40-*97 g the too thed wheel 35 is in partial enga ement with the part 40mof the wheel 40.-h9 and'the'part 97 of said wheel 'is in 'meshing alinement with the counter-- shaft wheel 3 7 'The wheel 404-97 is slidable axially along theflay shafts-96,11 strikin -foi'k working von the ,collar 95 being provi ved to effect/the `.sliding movement -wh'en reverse To put it into reverse the wheel 40-97 is slid backward so that the part 97 of rsaid wheel is brought into' mesh with the wheel 37, the larger part 40 of said wheel vmeantime remaining in mesh with the wheel sure permanent engagement of the-wheel 40 therewith inv either 'y ahead or. reverse positions. v

l A sleeve 41 is keyed at 42 to the cou'pler shaft 8; the forward part 43 of this sleeve is Castella/ted and carries a yoke collar 44 which is slidable upon it endwise but is ro# tated with it. A striking fork 45 on the end of the gear rod 46 moves this yoke collar 44 forward or aftas required. A 49 Working against the bearing 47 as a seating normily keeps thema 46 pushed for.. ward and the dog teeth 53 on the yoke coi-- 54 which are formed on the `contiguous faces ofthe toothed ring 50 which is mounted on `the sleeve 41. As the striking fork 93 and lthe striking fork 45 are both fixed to the. rod 46 the disengagement' of )the dog clutch Wheel 37and forward driving collars 21, 29 or 32 without reverse is required a movement of the hand lever pushes the clutch 26rearward so as to engage its rollers 20 with the shaft-.34 and simultaneously slid/es the wheel 97 into'- engagement with the wheel 37 and at the same .time locks the'yoke collar 44 to the toothed Bring 50 whereby the toothed ring 50, is in i effect fixed to the coupler' shaft 8. The engaging clutch consists of collar portion 26, barrel 27, engaging rollers 20, and ramp faceson the interior of the --drum portion 53.' As shown in Fig. 1 the rod 46 is in the/extreme forward position,

engaging clutch rollers' 20 are in alinement condition, the rotation'of the engine is not communicated to any part of the gearing,

the construction-that if the. engine should back fire ...while vjof the back refwillybeycommunicatd directly through the coup-lershaft 8 to the crown wheel 9 and' drivenA elementl 'and so danger. of accident to the chauffeur will be avoided. It willvbe seen, therefone,.that in reversing mechanism ies-disengaged, ,the layshaft wheel 40%97 being, however; rotatedA 35, the tooth of which is extra long to in lar 44 out of engagement with the dog teeth.

be moved over the intermediate or anyof the 'disturbing the reversing arrangement; when the strikin g fork that is with the reverse disengaged and the with ithe neutral or free ring 36. In this` but it may be remarked it is incidental to being cranked up', the,- rollers'83 willin'stantly grip and the shock coiled .spring 53-54 is simultaneous-with the disengage;

lOl

the neutral and'inthe ahead-.positions all the rotatably mounted ward or backward simultaneously.

i wheel 39 is rotated counter-clockwise.

any by the toothed wheel a while the shaft 34 is in rotation. The face of the toothed wheel 35 is longer than the faceof the other` wheels,'the additional length being provided toallow partial engagement of said wheel with the lay shaft wheel 40 under normal running, and to permit also full-engagement therewith during astern drive. Any mechanical structure may be used for sliding the wheel 40-97 and the dog clutch :53 forruns free when the countershaft 4 is mov- A counterclockwise in passing Y sequently,

i and 36,'as the Athese variations are ing clockwise while being driven through the intermediate or lay shaft Wheels 40-97. Then the gear is set in reverse and the clockwise movement of the shaft 34 becomes through the lay shaft wheel 40-97 and clockwise again when communicated to the countershaft wheel 37, then the countershaft wheel 39 moves clockwise and under those circumstances the clutch rollers 51 run free.

reverse drivev cannot be applied through the coupler shaft 8, the pinion 11, and the crown wheel 9, unless the wheel 50 is locked to the sleeve 41. .This locking is effected as before described by sliding the yokecollar 44 backward until the dog teeth ..53 thereon engage'the dog teeth 54 which are offset from the side .of the wheel 50. When this engagement is effected the clockwise movement of the `countershaft 4 is transmitted through the wheel 50, the dogclutch, sleeve 41, and the coupler shaft 8,'

to the pinion 11 and thence to the crown wheel 9, which then applies reverse motion to thev driven element.

Considerable` clearance. is left between the teeth 53 and 54 in the dog clutch. The

I barrel 27 consists of a collar 55 ycontaininga liner 56 having pockets 19"'c`ut in it, which pockets have aninclined outer face v18,. In each of said pockets a roller 2O is, set. These rollers 20 act as free wheel rollers land engage the liner 56', and lwith it'vthe collar 55, to

that one of the shaft collars 21, 29, 32, 34 case may be, with lwhich the rollers 20 are forvthetime being set.A Obviously, balls or hanging cams may be used instead of rollers in'the clutch pockets 19 whereby la similar wed'ging7 grip is effected between th'e rclutch and the shaft collar with which it Bis in alinement; but not illustrated because they .are known mechanical substitutes for Con- to the sleeve 41 the lroller grip in clutches of the free wheel-type. 4.

The operation is as follows: V

Dif/'ect` driver-The, engaging clutch is moved backward by' means of the hand lever rod 48 until its rollers 20 are in alinement with the collar 21. The engine being then driven its motion` is communicated through its shafts 7 and 13 and l through-the clutch rollers 20 and collar 21 to the coupler shaft 8 and the motion of the coupler sha-ft is transmitted to the pinion 11 and crown wheel 9 to the,driven element.

Intermediate speech-The engaging clutch is slid by means of the hand lever rod 48 until its rollers 20 are in alinementfavith the collar 29. The'engine being now rotated, its motion is transmitted through the shafts 7 and 13 and the clutch rollers 20 and collar 29 to the. shaft 28 and tooth wheel 30. The clockwise motion of the wheel 30 is transmitted into counter-clockwise movement onthe shaft 4 through the toothed wheel 38 which' is in engagement with said wheel 30. The counter-clockwise Ymovement of t-he wheel 39 which is keyed tot the countershaft 4 is transmitted into clockwise movement on the wheel 50. The wheel 50 engages the sleeve 41 by means of the clutch rollers 51 and as the sleeve 41 isl keyed at 42 to the coupler shaft 8, the coupler 11 and crown mitted through the pinion The relawheel 9 to the driven element.

tive diameters of the wheels 30, 38, 39 and the wheel .33 is transmittedfto the counter` shaft 41 as counterclockwise movement through the toothedwheel 37. The counterclockwise movement of the counter shaft 4 is .transmitted Vback through the toothed wheels 39 and which is keyed at 42 to the K shaft is moved clockwise and its motion is trans-..

50 and the clutch rollers 51' v coupler shaft 8 and is thence transmitted through the pinion 11l and the crown wheel 9 to the driven element. NeutraZ.-The clutch being set as shown in" Fig. 1 rotates thelidle ring 36 but does not move any of the gearing.. Rcaerger-' Thel engaging clutch vbeing rod 48 until the rollers 20 are in alinement with the surface 'of the shaftl34, clockwise movement isf-applied toV said shaft in the manner before4 described. At the Sametime,

the head 92- of the rod 46 pushessaid rod and the striking forks' 93 and 45 thereon 4.moved backward by means of the handlever I the contact, of the endl 52 ofthe rodv 48gwith backward. This backward movement of these striking forks yhas two effects, it slides back the wheel 40-97 until the wheel 97 is in engagement with the counter shaft wheel 37 ,l the wheel 40 being still in engagement with the wheel 35 on said shaft 34. It also moves backward the collar 44 and brings ,the

clockwise movement of the wheel 50 with which the countershaft wheel 39 gears and kthis .counter-clockwise movement of the wheel `5O is applied to the coupler shaft 8 through the collar 44,and the castellation 43 on the sleeve 41 and the counter-clockwise movement of the coupler-shaft 8 is then transmitted through the pinion 11 and the crown wheel 9to` the dri-ven element. I

The engine shaft 7 is not -usually connected directly to the engine crank shaft 80. A clutch 81 (see Fig., 2) operated by pedal lever is usually provided to enable the engine to be totally disconnected from the' gear when required.

I claim t- `-l. In variable speed gearing, the combination ofa driving shaft with tubular end and castellated exteriorly, a driven element, a coupler shaft carrying the driven element and journaled at its lforward end within the tubular end of the driving shaft, a collar fixed on said coupler sha t, a gear wheel vmounted as a free wheel upon said coupler shaft, a plurality of concentric tubular shafts mounted on said coupler shaft, a gear wheel keyed to each of said` tubular shafts, a countersliaft, ear wheels-keyed thereto in permanent mes with the-gear -wheels be'- fore mentioned, collarson the other ends of said tubular shafts 'of the same diameter as h th coupler shaft collar,- and a clutch of the nai-.ion 'of a. driving sha freewheel 'type rotated bythe castellated driving shaft` and movable along the same to a ine with any one'of said collars.

e 2.' In. variable speed,4 earing, the eombift with Atubular end and castellated exteriorly, a driven element,

ai'coupler shaft carrying the driven element andIj-ournaled at its forward'end within the tubular'end of the drivin shaft, a collar fixed on said' coupler sha t, a gear wheel Amountedas a lfree wheelupon said coupler shaft, a plurality of concentric tubular shafts mounted on said .coupler shaft, a gear wheel keyed'toeach ,of said tubular shafts, lockl va counter-shaft, ear wheelsykeyed' thereto inpermanent mes with the'gear wheels before mentioned, collars Aon the other endb of said tubular shafts of the same diameter asV the coupler shaft collar, a clutch of the free wheel type rot-ated by the castellated drivlng shaft and movable along the same to.

3. In variable speed gearing, the combination of a drivirig shaft with tubularv end and castellated exteriorly, a driven element, a coupler shaft carrying the driven element land' journaled at its forward end within the tubular end of the driving shaft, a collar fixedon said 'coupler shaft, a gear wheel mounted as a coupler shaft, a plurality of concentric tubular shafts mounted on said coupler shaft, `a gear wheel keyed to each of said tubular shafts, a counter shaft, gear wheels keyed vthereto in permanent mesh with the gear wheels before mentioned, collars on the other ends of said tubular shafts of the samediameter as the coupler shaft collar, a clutch of the, free wheel type rotated by the castelfree wheelv upon said i lated driving shaft and 'movable along the same to aline with any one of said collars and aclutch of the free wheel type interposed between the driving shaft and the coupler shaft, which clutch engages automatically lwhen the speed of the coupler shaft exceeds the speed of the driving shaft. 4. In a variable speed gearing,

driven element geared with said vcoupler shaft, a countershaft parallel driven element, a' plurality of tubular shafts mounted on the coupler shaft, 4gear wheels keyed to said. tubular shafts and to said counter shaft and in permanent mesh, a free a couplerl shaft, a driving shaft coaxial therewith, a

wit-l1 said wheel gear on said coupler shaft in per-` manent mesh with a gear on said 'oo unter4 shaft, means for locking said free wheel geary Vto the coupler shaft, a gear on one-of said tubular. shafts and a gear on the countershaftaan intermediate gear `wheel in permanent mesh with said gear'on said tubular shaft and slidable into engagement with said ear on the counter shaft, collars of uniform diameter on saidl coupler shaft and tubular shafts, a clutch of the free wheel type slidably mounted on thedriving element, a rod forsliding said clutch into alinement with any one of said collars and for closing the 'ng ,means between the coupler shaft andits free wheel gear, and simultaneously sliding the intermediate gear wheel into enga'gement.'

5 In-a variable speed gearing of the class herein described, a coupler shaft and a gear wheei mounted thereon, a drivingishaft, an ahead clutch between the said coupler shaft and the said gear wheel, tubular shafts,l an ahead clutch transmitting motion from the driving-shaft to the said tubular shafts, and a reverse clutch between the coupler shaft and the said driving shaft for engaging the same thereto when moving at a faster rate than said driving shaft.

6. In a variable speed gearing a driving shaft, a counter shaft, an ahead clutch a coupler shaft directly geared to said l counter shaft through said ahead clutch, I means for locking said clutch, and tubular yand a reverse shafts mounted on said coupler shaft, gears on said tubularshafts, -gears on the counter shaft meshing with said gears on the said tubular shafts, an ahead clutch through which said tubular shafts and said counter shaft are eng'geable to the driving shaft, clutch between the coupler shaft and the driving shaft.

In testimony whereof I have affixed my signature in presence of two witnesses.

GEORGE THOMAS lCAVILL.`

Witnesses:

N. J. CANDRICK, W. J. DAVIS. 

